HITCHCOCK AND CHASE NOBTH AMERICAN PANICUM. 



195 



111. Panicum y ad kin ens e Ashe. 



? Panicum dumuz Desv. Opusc. 8S. 1S31. "Habitat in America calidiori." The 

 type, in the Desvaux Herbarium, is a fragment of a branch of some species in this 

 group. The immature, glabrous spikelets, 2.3 mm. long, the second glume and sterile 

 lemma pointed beyond the fertile lemma, suggest P. yadkinense, though it may be 

 P. barbulatum, the pointed spikelets being due to immaturity and withering. 



Panicum maculatum Ashe, Journ. Elisha Mitchell Soc. 15: 44. 1898, not Aubl. 1775. 

 "Collected by the writer at Raleigh, X. C, May. 1895." The type of this could not 

 be found in Ashe's herbarium. In the National Herbarium is a specimen labeled in 

 Ashe's handwriting, '"'Panicum maculatum, Raleigh, May, 1895" which is probably 

 a duplicate type. This plant belongs to the species here described though it does 

 not agree in all respects with the original description of Panicum maculatum. The 

 spikelets are there said to be f lines long, and '"'about the size of those of P. barbu- 

 latum" [P. microcarpon of this monograph], and the species is said to be distinguished 

 from P. dichotomum by the smaller spikelets. The specimen from Raleigh has spike- 

 lets larger than those of P. dichotomum, being about 2.5 mm. long. Since this speci- 

 men belongs to the species as understood by Ashe, it is probable that the description 

 of the spikelets was based upon an admixture of P. microcarpon, as the two species 

 are frequently found growing together. 



Panicum yadkinense Ashe, Journ. Elisha Mitchell Soc. 16: 85. 1900. Based on 

 "P. maculatum Ashe, not P. maculatum Aubl." 



DESCRIPTION. 



Vernal form similar to that of P. dichotomum but culms taller and stouter, some- 

 times 1 meter high; sheaths usually bearing pale, glandular spots; blades 9 to 13 cm. 

 long, 8 to 11 mm. wide, panicle about 10 to 12 cm. long, about three-fourths as wide, 

 the long lower branches ascending; spikelets 2.3 to 2.5 mm. long, 1 mm. wide, elliptic 

 to subfusiform, pointed, glabrous; first glume about 

 one-third the length of the spikelet, usually blunt; 

 second glume and sterile lemma rather faintly 

 nerved, equal, exceeding the fruit and forming a 

 slight point beyond it; fruit 1.9 mm. long, 0.9 mm. 

 wide, elliptic, subobtuse. 



Autumnal form erect or leaning, loosely branch- 

 ing from the middle nodes, the blades smaller but 

 not conspicuously reduced. 



This species differs from P. dichotomum in the 

 vernal form in its larger size and longer, acute 

 spikelets, and in the autumnal form in the com- 

 paratively few branches, which do not form a bushy crown. Occasionally the 

 branches are rather numerous, though not closely fascicled and bushy, for example, 

 Harper 1349, and Porter from Pennsylvania in 1895. The following two specimens, 

 Chase 3072 and Hitchcock 1416, are referred to this species, though the spikelets are 

 scarcely over 2 mm. long; that is. the second glume and sterile lemma do not extend 

 into a point as in typical spikelets. 



Fig. 195.— P. yadJiimme. From dupli- 

 cate type specimen of P. maculatum 

 Ashe in National Herbarium. 



DISTRIBUTION 



Moist woods and thickets, Pennsylvania to Georgia, west to southern Illinois and 

 Louisiana . 



Pennsylvania: Easton, Porter in 1895. 



Illinois: Makanda, Gleason in 1903; Johnson County, Schneck in 1902 (Hitch- 

 cock Herb.). 



